Hi Pandey,
Whether with 4.9 or 4.10, you just need to setup "sticky cookies" on your load balancer (whether you have physical hardware for that, or using software). That is, once a user has been assigned to 1 or the 2 servers for a given session, that user should be sent again to the same server in any subsequent request.
Alex
--
Follow Orbeon on Twitter: @orbeon
Follow me on Twitter: @avernet